<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<style>
    h1::before {  
  transform: scaleX(0);
  transform-origin: bottom right;
}

h1:hover::before {
  transform: scaleX(1);
  transform-origin: bottom left;
}

h1::before {
  content: " ";
  display: block;
  position: absolute;
  top: 0; right: 0; bottom: 0; left: 0;
  inset: 0 0 0 0;
  background: hsl(200 100% 80%);
  z-index: -1;
  transition: transform .3s ease;
}

h1 {
  position: relative;
  font-size: 5rem;
}

html {
  block-size: 100%;
  inline-size: 100%;
}

body {
  min-block-size: 100%;
  min-inline-size: 100%;
  margin: 0;
  box-sizing: border-box;
  display: grid;
  place-content: center;
  font-family: system-ui, sans-serif;
}

@media (orientation: landscape) {
  body {
    grid-auto-flow: column;
  }
}
</style>
<body>
    <h1>Hover Me</h1>
</body>
</html>